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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 53 (1969)

Issue: 3. (March)

First Page: 726

Last Page: 726

Title: Neocurrent Trends and Structural Control of Sedimentation in Wilmington Submarine Canyon, Eastern United States: ABSTRACT

Author(s): Gilbert Kelling, Daniel J. Stanley

Article Type: Meeting abstract

Abstract:

Neocurrent trends, patterns of sediment transport in the geologically recent past inferred from preserved vectorial properties, indicate that sediment is moving predominantly toward the west-southwest on the outer shelf off the U.S. east coast. Sediment is being trapped by the north-south-trending head of the Wilmington submarine canyon. Seismic-reflection profiles, direct observation of the bottom with camera and underwater television, and sampling reveal that (1) a greater thickness of the unconsolidated sediment wedge drapes the eastern canyon wall and (2) the percentage of pebbles, coarse sand, and shell exceeds that on the west flank. Coarse sediment, largely of relict origin, consists of Pleistocene and Tertiary materials some of which have been reworked recently fr m the canyon walls.

Cognizance of the structural framework is essential in interpreting the morphologic and sedimentary patterns of the canyon. The sharp northward bend of the canyon head and its shelfward migration is controlled largely by faulting (probably pre-Quaternary) and Pleistocene drainage as shown in subbottom profiles. Draping of deeper, probably pre-Pleistocene, subbottom reflectors into the outer part of the canyon head suggests that this canyon formed before the Pleistocene. A morphologic high (Nyckel ridge) forming the southern margin of the canyon on the slope and upper rise is recognized as a compound flexure of structural origin. This feature is not a simple depositional levee as has been suggested. It serves as a locus for bottom current activity on the lower slope and rise and contro s the textural distribution in the area. Intrabasinal slumping off this ridge is important.

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Copyright 1997 American Association of Petroleum Geologists